Typewriter



Oct 9; 1945. w. w'. DAVID'SON I ,386

TYPEWRI TER 4 Fil d Oct. 28, 1944 Mirror Type Ac'tuut ing & CurridgeCon1roi Mechanism RutchetLine Spacer Moving INVENTOR. Back of RollUpward @/fiazg figmffia fl WWW gay;

Patented Oct. 9, 1945 William Ward Davidson, Evanston, 111., asslgno toDavidson Manufacturing Corporation, a corporation of IllinoisApplication October 2 8, 1944, Serial No. 560,774

7 9 Claims.

In certain forms of duplication or printing, copies are made directlyfrom the master sheet or plate. For example, in direct lithographicprinting a plate is prepared which bears a reversed image of the matterto be printed. This reversed image (often called mirror image) isreversed in applying it to the copy sheet so that as thus printed on thecopy sheet it appears in final form.

For oflice duplicating or printing the most common subject-matter to beprinted is typewritten matter. This has been done in the pastprincipally by stencil, gelatin or spirit duplicating, but there hasbeen no comparably inexpensive way of reproducing typewritten mattersatisfactorily by the lithographic process- To the extent that thelithographic process has been used in the field, it has been the ofisetlithographic process rather than the direct lithographic process whichhas generally been used. There has been no simple and efiective,inexpensive way to reproduce typewritten material by. directlithography. In this instance the matter was typed onto-a plate, such asa flexible sheet of aluminum or paper-backed aluminum foil and the platewas put on a press having an offset blanket onto which the plate wouldprint a reversed image so that the blanket in turn could print a normalimage on the copy sheet.

According to the present invention the blanket becomes unnecessary byvirtue of providing a practical manner of producing a reversed image ofthe plate. The omission of the blanket permits various simplificationsand economies, so that a direct lithographic press can be produced andsold at a lower price than an offset lithographic press.-

The reversed image is produced directly on the plate by a speciallyconstructed typewriter in which the type is reversed as compared toordinary twpewriter type, so that instead of producing a normal letterit will produce a reversed letter. It has been suggested heretofore todo this, and to have the carriage move during typing from left to rightinstead of from right to left so that each line would begin at theright-hand side of the sheet. Of course, it is necessary in reversedtyping to have each line read from right to left, so that afterreproduction and the reversal inherent therein the line will read fromleft to right. However, in typing according to this previous suggestionthe reversal of the lines, together with the reversal of the individualletters, made the work very hard and confusing for typists to read, evenwhen a mirror is provided.

According to the present invention the carriage moves from right to leftduring yping (when viewed from the operators position at the front 01'the-machine) which is the same direction as conventional typewriters,but the type strikes against the paper at the rear side of the roller,the side remote from the operator. Thus the operators left is theright-hand side of the face of the sheet being typed. A mirror isprovided beyond the roll so that the operator can glance at the mirrorand easily read or check her work. which she is typing is reversed sothat it appears to be normal typing.

The line spacing mecha'nismoperates to turn the roll in the reverseddirection. as compared with a normal typewriter, so that the paper movesupwardly behind the roller. It will be observed that the manualoperations of the typist and the view which she gets in the mirror arethe same as conventional typewriter-Sn Hence, an operator accustomed toconventional typewriters will have no difiiculty in producing a reversedimage plate on this special typewriter. She will hardly be aware thatshe is looking in a mirror. She will type in the usual way,. with nomore efiort, and after each line she will shift the carriage in theusual direction and with the usual incidental eifort of turning the rollin the right direction to advance the sheet. Of course, she will putsheets in at the front side of the roll instead of the rear side, butthis will be the obvious thing to do since the guide plate will be atthe front instead of at the back. The work will be as accessible forerasures as if she were typing at thefront of the roll. In fact, in asmuch as the type mechanism will be at the rear of the roll, the rollwill be further forward on the machine than usual, and hence will becloser to the operator for erasures.

A typewriter constructed in accordance with this invention will be veryuseful for other types of duplicating requiring reverse image mastersheets, such as spirit duplicating, for example. It is especiallyimportant, however, for processes such as lithographic processes whichmay use a fairly heavy master .sheetor plate which prevents theobtaining of sharp characters by striking through the sheet against acarbon paper.

Additional objects and advantages will become apparent from thefollowing description and from the drawing, in which Fig.1 is adiagrammatic representation of the side view of the form of inventionchosen for illustration;

In the mirror the mirror-image work Fig. 2 is a diagrammatic plan viewthereof;

Fig. 3 is a face view of an example of positive image type which wouldbe used in accordance with this invention for reversed image typing; and

Fig. 4 is an illustration of the resulting reversed image typing.

Although the law requires a full and exact description of at least oneform of the invention, such as that which follows, it is, of course, thepurpose of a patent to cover each new inventive concept therein, nomatter how it may later be disguised by variations in form or additionsof further improvements; and the appended claims are intended toaccomplish this purpose by particularly pointing out the parts,improvements, or combinations in which the inventive concepts are found.

In the illustrations of the invention only the features characteristicof the present invention and features necessary to the understandingthereof are illustrated, since the general details of construction oftypewriters are so well known in the art as to need no illustration ordescription.

According to the invention the main typewriter frame ll carries asuitable keyboard, comprising keys l2 at the front thereof which actuatetypecarrying arms such as the arm l3 shown in dotted lines, one armbeing actuated by each key in response to mechanism carried by the frameI I. A carriage, diagrammatically represented by the dotted outline I4,is mounted on the frame I I for reciprocation thereon in the usual way.

To indicate that the carriage is biased toward the left, a conventionalspring-actuated carriage moving roll I6 is illustrated in Fig. 2. Whenthe carriage is shifted to the right the band I! is drawn out from theroll It, thus turning the roll 16 and winding the spring therein. Aseach key or space bar is pressed a conventional escapement mechanismpermits the carriage to be drawn to the left the distance of one letterspace, under the influence of the spring roll 16 and band I1.

Since the purpose of this invention is to type reversed image plates andthe like, this can be accomplished with the carriage moving in thedirection indicated if positive image type, such as shown in Fig; 3,strikes the paper on the rear side of the paper-carrying roll, asclearly indicated in Fig. 1. Accordingly the type-carrying arms l3 arearranged to move against the rear side of the roll l8, as indicateddiagrammatically in Fig. 1. The actuating mechanism may comprise anysuitable mechanical linkage, or it could comprise the electricaltype-actuating mechanism simply turned around to face the rear of theroll as it has heretofore faced the front of the roll, the circuits tothe keys remaining electrically unchanged.

A mirror 2| is so positioned that the typist typing on the keys l2 canlook into the mirror 2| and check the work as it proceeds, adjust thepaper, etc. The mirror'could be carried by the frame I I, but it is atpresent preferred to mount it rigidly on the carriage l4 so that itmoves with the carriage and, without being any longer than the roll l8,will permit reading the entire line, regardless of the position of theroll. The mirror could be adjusted for tilting about an axis parallel tothe axis of the roll, or for other movement parallel to the axis, butthe Vertical position illustrated is believed to be most desirable sinceit on conventional typewriters.

with it the typed matter and roll will appear to the typist exactly asshe is accustomed to seeing Of course, the usual line guide would becarried by the frame ll adjacent the roller l8, so that it would alsoappear in the mirror 2| and enable the operator to see just where a keywould strike. Also the mirror may be removable, if desired, or movablein any way to give better access to the machine for. changing the ribbon2D, cleaning the type, etc., the ribbon and type being naturallypositioned to the rear of the roller.

Of course, the paper should be fed to the roll I A directionautomatically, the usual ratchet mechanism will be varied to operate inthe opposite direction than is customary, this ratchet mechanism beingindicated diagrammatically at 24. The ratchet mechanism will be actuatedby a carriage return lever 26, which may be conventional except asrequired by the reversed ratchet mechanism.

The conventional paper-feeding and holding pressure rollers 21 areprovided, together with all other guiding, feeding and adjusting means.Shiftable pressure rollers 28 will be provided at about the positionillustrated to 'hold the typed or upper portion of the sheet or platedown out of the line of vision between the typists eyes and the mirror2|.

When the operator desires to turn the roll by means of one of the knobs29, the direction to turn it will be obvious and so it will cause her noconfusion even though she turns it in the opposite direction for raisingthe typed lines than she is accustomed to. If this should proveconfusing to some operators, the knobs could be mounted on a gearmeshing with the gear carried by the roller. The operator, desiring toraise the typed lines, would then turn one of these knobs in the samedirection as that to which she is accustomed in raising the typed linesof a conventional typewriter. The ratchet line spacing mechanism couldalso be carried by this gear, in which case conventional ratchetmechanism could be used, the reversing being accomplished by the gears.However, the spring detent mechanism for line positioning should bedirectly associated with the roller to avoid any undesired effects dueto play in the gears.

Of course, any other conventional or desirable features may be added tothe illustrated machine. No attempt has been made to show the parts intheir true proportions. It should be noted, for example, that the keys12 would, ex-

cept in portable machines, probably be spaced considerably further belowthe roll than has been illustrated. This would not only be in accordancewith conventional practice, but would give more clearance so that itwould be easier to position the guide 22 so as to hold the sheet whereit would not obstruct the typists view either to the keys l2 or to themirror 2|. This guide plate could be made adjustable, if desired to suitthe convenience of different operators.

From the foregoing it is seen that a highly practical typewriter isprovided for typing reversed image matter on lithographic plates or ingit. Although the sheet is fed to the front of the roller instead of theback, this causes no confusion inasmuch' as the guide plate 22 clearlyindicates where to feed it.

I claim as my invention:

1 A typewriter for producing reversed image work including a keyboard atthe front of the machine, a carriage including a roller for carrying thesheet to be typed, type mechanism controlled by the keys and adapted tostrike the sheet at the rear side of the roller and to produce areversed image thereon, carriage-control mechanism adapted to move thecarriage from right to left as the typing proceeds, line spacing andcarriage return means adapted to return the roll and move the rear ofthe roll upwardly, and a mirror carried by the carriage positionedrearwardly of the roll and facing forwardly, suitably disposed for theoperator using the keyboard to view the line beingtyped.

2. A typewriter for producing reversed image work including a keyboardat the front of the machine, a carriage including a roller for carryingthe sheet to be typed, type mechanism controlled by the keys and adaptedto strike the sheet at the rear side of the roller and to produce areversed image thereon, carriage-control mechanism adapted'to move thecarriage from right to left as the typing proceeds, line spacing andcarriage return means adapted to return the roll and move the rear ofthe roll upwardly, and a mirror positioned rearwardly of the roll andfacing forwardly, suitably disposed for the operator using the keyboardto view the line being typed.

3. A typewriter for producing reversed image work including a keyboardat the front of the machine, a carriage including a roller for carryingthe sheet to be typed, type mechanism controlled by the keys and adaptedto strike the sheet at the rear side of the roller and to produce areversed image thereon, carriage-control mechanism adapted to move thecarriage from right to left as.the typing proceeds, manually operatedcombined line spacing and carr'iagereturn means adapted to return theroll and move the rear of the roll upwardly, and a mirror positionedrearwardly of the roll and facing forwardly, suitably disposed for theoperator using the keyboard to view the line being typed.

4. A typewriter, for producing reversed image work including a keyboardat the front of the machine, a carriage including a roller for carryingthe sheet to be typed, type mechanism controlled by the keys and adaptedto strike the sheet at the rear side of the roller and to produce areversed image thereon, carriage-control mechanism adapted to move thecarriage from right to left as the typing proceeds, and line spacing andcarriage return means adapted to return the roll and move the rear ofthe roll upwardly.

5. A typewriter for producing reversed image work including a keyboardat the front of the machine, means for holding a member to be typedexposed for typing on the face thereof remote from the operator, typeadapted to produce reversed image characters, means controlled by saidkeyboard for impressing the type against said remote face, and a mirrordisposed for the typist operating the keyboard to view the typing topresent a'normal view thereof;

6. A typewriter for roducing reversed image work including-a keyboard atthe front of the machine, means for holding a member to be 'typedexposed for typing on-the face thereof remote from the operator, typeadapted to produce reversed image characters, means controlled by saidkeyboard for impressing the type against said remote face, a mirrordisposed for the typist operating the keyboard to view the typing topresent a normal view thereof, and means for holding the member so itdoes not obstruct the typists view of the mirror or of the keyboard.

7. A typewriter for roducing reversed image work including a keyboard atthe front of the machine, means for holding a member to be typed exposedfor typing on the face thereof remote from the operator, type adapted toproduce reversed image characters, and means controlled by said keyboardfor impressing the type against said remote face.

8. A typewriter for producing reversed image work including a keyboardat the front of the machine, a carriage including a roller for carry-.ing the sheet to be typed, type mechanism controlled by the keys and'adapted to strike the sheet at the rear side of the roller and toproduce a reversed image thereon, carriage control mechanism adapted tomove the carriage from right to left as the typing proceeds, andmanually operated combined line spacing and carriage return meansadapted to return the roll and move the rear of the roll upwardly.

9. A typewriter for producing reversed image work including a keyboardat the front of the machine, means for holding a member to be typedexposed for typing on the. face thereof remote from the operator, typeadapted to produce reversed image characters, means controlled by saidkeyboard for impressing the type against said remote face, and means forholding the memberso it does not obstruct the typlsts view of the mirroror of the keyboard.

WILLIAM WARD DAVIDSON.

